1. Field of the Invention
The present invention generally relates to a method and apparatus for v-bank filter bed scanning.
2. Description of the Related Art
Many contamination control applications having high airflow requirements utilize v-bank filters over panel filters when laminar flow is not of primary concern. However, conventional manufacturing and validation practices limit testing of v-bank to overall efficiency test due to the inability to accurately leak test (i.e., scan test) the filter media for pin hole leaks. The inability to scan test v-bank filters has been documented in an article published October, 2001 in Cleanrooms Magazine entitled “EN1822: THE STANDARD THAT GREATLY IMPACTED THE EUROPEAN CLEANROOMS MARKET.” In the article, the author states that “ . . . HEPA/ULPA filters with V-shaped pleat packages cannot be scanned, because the measuring probe cannot be brought close enough to a possible leak in the pleated package.”
However, many facilities are forced to utilize deep pleated filter products instead of v-bank filter products because of increasingly stringent validation requirements for contamination control that require scan testing. As deep pleated filters generally do not have the air handling capacity of v-bank filters, more filters may be required for a given application, and more energy may be required to drive gas flows through the filters. Thus, the use of deep pleated filters in applications where v-bank filters could be utilized may realize higher filter and energy usage costs.
Therefore, there is a need for a method and apparatus for scanning v-bank filter beds.